新疆伊吾县宝山铁矿地质特征、成矿模式与找矿方向

GEOLOGICAL CHARACTERISTICS AND METALLOGENIC MODEL OF THE BAOSHAN IRON DEPOSIT AND SOME PROSPECTING INDICATORS IN THE YIWU COUNTY, XINJIANG

宝山铁矿位于新疆东准噶尔晚古生代岛弧岩浆-构造成矿带东部,位于琼河坝铁铜多金属矿集区.宝山铁矿为由热液交代成因夕卡岩型磁铁矿矿体和黄铜矿-磁铁矿矿体、贯入成因夕卡岩型磁铁矿矿体和热液充填型黄铜矿矿脉构成的铁矿床,目前开采的主要为磁铁矿型铁矿.矿区岩浆岩类型多样,主要有花岗岩、辉长岩和辉绿玢岩.从矿体被花岗岩穿插及贯入型磁铁矿中含Co高等特征推断,主成矿岩体可能为隐伏的辉长岩.矿区深部存在规模较大的含矿夕卡岩质成矿流体"生产车间",含矿夕卡岩质流体的形成与迁移是脉动的,成矿后期以铜的成矿为主.宝山铁矿下步的找矿重点应放在对露天采坑深部隐伏铁矿和矿区深部隐伏铜矿的预测与探查.

The Baoshan iron deposit in the Yiwu county, Xinjiang, is located in the Qiongheba Fe-Cu polymetallic deposit cluster situated in the eastern of the Zhungaer later Paleozoic island arc-type magmatism - tectonics - mineralization belts. The Baoshan iron deposit consists of skarn-type magnetite and pyrite- magnetite ore bodies formed by hydrothermal metasomatism, skarn-type magnetite ore bodies injected along fractures or faults, and hydrothermal chalcopyrite veins filled along fractures respectively. The magnetite ore bodies are the main ores exploited in the Baoshan iron deposit at present time. There are abundant of magmatic rocks, including granite, gabbro and diabase. Evidences that some magnetite ore bodies was intruded and cut by granite and some magnetite ores contain high Co elements indicate that the oreforming intrusive bodies are most likely some gabbro located in deep position of the Baoshan iron deposit. There was possible a big ＂factory＂ producing the skarn-typc ore-forming fluids in the deep area of the ore district, and formation and migration of these ore-forming fluids are possible periodically. The copper ore bodies were mainly formed in the late metallogenic stage. We suggest to prospect the deep buried magnetite ore bodies under the open pit and the hidden copper deposit in the deep position of the ore district in the further exploration for the Baoshan iron deposit.